Effects of miR-33a-5P on ABCA1/G1-mediated cholesterol efflux under inflammatory stress in THP-1 macrophages

PLoS One. 2014 Oct 17;9(10):e109722. doi: 10.1371/journal.pone.0109722. eCollection 2014.

Abstract

The present study is to investigate whether inflammatory cytokines inhibit ABCA1/ABCG1-mediated cholesterol efflux by regulating miR-33a-5P in THP-1 macrophages. We used interleukin-6 and tumor necrosis factor-alpha in the presence or absence of native low density lipoprotein (LDL) to stimulate THP-1 macrophages. THP-1 macrophages were infected by either control lentivirus vectors or lentivirus encoding miR-33a-5P or antisense miR-33a-5P. The effects of inflammatory cytokines, miR-33a-5P and antisense miR-33a-5P on intracellular lipids accumulation and intracellular cholesterol contents were assessed by oil red O staining and quantitative intracellular cholesterol assay. ApoA-I-mediated cholesterol efflux was examined using the fluorescent sterol (BODIPY-cholesterol). The gene and protein expressions of the molecules involved in cholesterol trafficking were examined using quantitative real-time polymerase chain reaction and Western blotting. Inflammatory cytokines or miR-33a-5P increased intracellular lipid accumulation and decreased apoA-I-mediated cholesterol efflux via decreasing the expression of ABCA1 and ABCG1 in the absence or presence of LDL in THP-1 macrophages. However, antisense miR-33a-5P reversed the effects of inflammatory cytokines on intracellular lipid accumulation, cholesterol efflux, and the expression of miR-33a-5P, ABCA1 and ABCG1 in the absence or presence of LDL in THP-1 macrophages. This study indicated that inflammatory cytokines inhibited ABCA1/ABCG1-mediated cholesterol efflux by up-regulating miR-33a-5P in THP-1 macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter 1 / genetics
  • ATP Binding Cassette Transporter 1 / metabolism*
  • ATP Binding Cassette Transporter, Subfamily G, Member 1
  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism*
  • Biological Transport
  • Cell Line
  • Cholesterol / metabolism*
  • Humans
  • Inflammation / metabolism
  • Interleukin-6 / pharmacology
  • Lipid Metabolism
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Macrophages / pathology
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Stress, Physiological
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • ABCA1 protein, human
  • ABCG1 protein, human
  • ATP Binding Cassette Transporter 1
  • ATP Binding Cassette Transporter, Subfamily G, Member 1
  • ATP-Binding Cassette Transporters
  • Interleukin-6
  • MIRN33a microRNA, human
  • MicroRNAs
  • Tumor Necrosis Factor-alpha
  • Cholesterol

Grants and funding

This study was supported by Major State Basic Research Development Program of China (973 Program, Nos. 2012CB517700 and 2012CB517500), National Natural Science Foundation of China (81070631, 81070317, and Key Program Nos. 81030008, 81270493, 81270789 and 81200567), and National Key Clinical Specialties Construction Program of China. The funders did not participate in study design, data collection and analysis, decision for publication, or the preparation of the manuscript.